Bioremediation of contaminated soil. Development and application of technologies

摘要

Bioremediation is a technology for remediation of soil contaminated by hazardous waste chemicals. The application of specific degrading bacteria for the treatment of polluted soil is emphasized. The current market and regulatory framework related to bioremediation are evaluated. Soil polluted by benzene, toluene, ethylbenzene, xylene (BTEX) and light fuel oil often contains indigenous hydrocarbon-degrading bacteria, and degradation is limited by the availability of oxygen or other factors. The degrading biomass may be inhibited or absent in soil heavily polluted by creosote or coal tar, and inoculation may initiate the degradation process. An inoculum may include a range of different bacterial strains. Fungi are more versatile. The degradation of tetrachloroethylene, trichloroethylene, and 1,1,1-trichloroethane in the environment is limited by the lack of effective degrader organisms. A TCE-degrading bacteria that grows on lactate has been constructed by genetic engineering, and research is being carried out to develop a bacteria with the capability to use the chlorinated aliphatics as growth substrates. Deviations in national guidelines for treatment of contaminated soil may inhibit the technical development of a bioremediation technology. Acceptance of high levels of rest contaminations in particular regions attract foreign soil, creating trans-national transport of polluted material. Prices of treatment are kept artificially low, and competitive incentives, such as technical developments, are inactivated. For easily degradable compounds such as BTEX and light fuel oil, the advantages of inoculation of soil with specific degrading organisms are limited. (AB) (19 refs.)